Ctype provides character class testing to Perl programs. The ctype.h functions are part of the C library (in your system!). Ctype also supports the Perl library ctype functions. To use the Perl library ctype functions, set the variable $Ctype::useperlfns to a non-false value. For the OO interface, call the method $obj->useperlfns to toggle it.

The OO interface constructor is called (by convention) new. new is called with a character as an argument. It creates a Ctype object that will perform tests on the character when called as an object method. These are the relations to the regular C functions: